#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define pii pair<int,int>
#define piii tuple<int,int,int>
#define mp make_pair
#define mt make_tuple
#define fi first
#define se second
#define deb(var) cerr<<#var<<'='<<(var)<<"; "
#define int long long
int n,m,a[300010],fa[300010],tag[300010];
priority_queue<pii,vector<pii>,greater<pii> > q[300010];
int u[300010],v[300010],w[300010],del[300010];

vector<int> ans;
int find(int i){return fa[i]==i?i:fa[i]=find(fa[i]);}
void upd(int i);
void chk(int u){
	while(q[u].size()&&a[u]>=q[u].top().fi+tag[u]){
		int x=q[u].top().se;
		q[u].pop();upd(x); u=find(u);
	}
}
void warn(int i){
	del[i]=1;
	int x=find(u[i]),y=find(v[i]);
	if(x==y)return;
	ans.pb(i);
	if(q[x].size()<q[y].size())swap(x,y);
//	tag[y]+=a[x],tag[x]+=a[y];
	while(q[y].size())
		q[x].push({q[y].top().fi+tag[y]-tag[x],q[y].top().se}),q[y].pop();
	fa[y]=x,a[x]+=a[y]; chk(x);
}
void upd(int i){
	if(del[i])return;
	int x=find(u[i]),y=find(v[i]);
	if(x==y)return;
	int T=w[i]-a[x]-a[y];
	if(T<=0)warn(i);
	else q[x].push({a[x]+(T+1)/2-tag[x],i}),
		 q[y].push({a[y]+(T+1)/2-tag[y],i});
}
void work(){
	cin>>n>>m;
	for(int i=1;i<=n;i++)cin>>a[i];
	iota(fa+1,fa+n+1,1);
	for(int i=1;i<=m;i++)
		cin>>u[i]>>v[i]>>w[i],upd(i);
	cout<<ans.size()<<'\n';
	for(auto i:ans)cout<<i<<' ';
}
signed main(){
	ios::sync_with_stdio(0),
	cin.tie(0),cout.tie(0);
	int T=1;while(T--)work();return 0;
}